The present invention relates to sensing systems for airframes, and more particularly, to a body referenced gimballed sensor system which may be utilized in conjunction with the flight control system of an airframe to provide proportional navigation of the airframe to a target.
In the past, the sensor of a homing airframe, such as a radar, electro-optical sensor, or acoustical sensor, has been mounted on a space stabilized gimbal so that the angular motion of the airframe is removed from the sensing and flight control systems. This requires the utilization of expensive and complex space stabilization mechanisms. Such mechanisms include rate gyros or precessible free gyros.
A less expensive approach has been to mount the sensor directly to the airframe, without containing any inertia sensors/stabilization. This eliminates the expensive and complex stabilization mechanisms. However, this approach leads to poor performance. Since the sensor is not mounted on a gimbal, its look angle is limited. Furthermore, with this approach, it is difficult to overcome problems attributable to static gain, static phasing, non-linearity, etc. of the sensor.